A former president of Purdue Pharma, the controversial drug manufacturer widely considered to have ignited the opioid epidemic through its aggressive marketing of OxyContin, has been awarded a patent for a new opioid addiction treatment.

Dr. Richard Sackler is one of the six individuals on the patent issued in January, the Financial Times first reported Friday. Critics expressed concern that Sackler, whose family is worth an estimated $13 billion largely from Purdue's sale of opioid painkillers, now stands to profit further from medication that treats addiction to the very drugs peddled by his family.

The patent covers a new formulation of buprenorphine in a wafer form. The medication is shown to help people struggling with opioid addiction, and the Food and Drug Administration has already approved the drug in tablet and film form.

President Donald Trump declared the opioid epidemic a nationwide public health emergency in October, citing more than 300,000 Americans who have died from opioid overdoses since 2000.